The presence of non-thermal phenomena in galaxy clusters is well established thanks to the detection of diffuse radio emissions, the presence of mergers, shocks fronts, and gas bulk motions, and clues about the presence of dark matter. The study of these non-thermal components is primary for a full comprehension of the physics of galaxy clusters and their use in cosmology, and is a currently open line research, involving observations in different spectral bands, theoretical modelling and data interpretation, and numerical simulations.
In this talk I will review some of the historical and present open questions regarding the non-thermal content of galaxy clusters, and possible ways to face them. I will also highlight some of my contributions to this topic, with a special attention to the possible role of annihilation of dark matter particles as a source of non-thermal electrons, and the use of the Sunyaev-Zel’dovich effect as a probe of non-thermal phenomena in galaxy clusters.

Breve CV del Dr. P. Marchegiani:

I obtained my MSc degree at the Universita’ Sapienza in Rome, with a thesis on the non-thermal Sunyaev-Zel’dovich effect in galaxy clusters, and my PhD at the Universita’ di Roma Tre, with a thesis on the non-thermal content of galaxy clusters. Later, I had several research grants and postdoctoral positions at the Universita’ Sapienza in Roma, at the Osservatorio Astronomico di Roma, and at the University of the Witwatersrand in Johannesburg.
My scientific research lines are the study of non-thermal phenomena in galaxy clusters, the Sunyaev-Zel’dovich effect and its use as a probe of galaxy clusters properties, the possibility of constraining the properties of dark matter in astrophysical objects, and the study of non-thermal phenomena in other extragalactic objects like blazars and radiogalaxies.
I recently joined the Osservatorio Astronomico di Cagliari, and have ongoing collaborations with the University Sapienza and the University of the Witwatersrand. I am currently involved in the compilation of the BZCAT catalog of blazars, in the MeerKAT Galaxy Clusters Legacy Survey, in three SKA Working Groups, in the H.E.S.S. collaboration, and in the preparation of the observation plans for the balloon-mounted mm and sub-mm telescope OLIMPO.